Year Number 1996 -0.0910280793905258 1998 0.575025260448456 2000 0.377964615821838 2002 0.467512369155884 2003 0.173525497317314 2004 0.00363073358312249 2005 0.14727059006691 2006 0.394421190023422 2007 0.357635468244553 2008 0.369860708713531 2009 0.353678971529007 2010 0.360091060400009 2011 0.301750302314758 2012 0.379833996295929 2013 0.170710384845734 2014 0.0785408988595009 2015 0.010424641892314 2016 0.0682793706655502 2017 0.321378797292709 2018 0.444267064332962 2019 0.56119829416275 2020 0.40158087015152 2021 0.364647597074509 2022 0.246252059936523